checkbox全选/撤销全选代码 _Web前端

checkbox全选/取消全选代码
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script src="jquery-1.10.2.js" type="text/javascript"></script>
<script language="JavaScript">
	$(function() {
		$("#ckAll").click(function() {
			$("input[name='sub']").prop("checked", this.checked);
		});

		$("input[name='sub']").click(function() {
			var $subs = $("input[name='sub']");
			$("#ckAll").prop("checked",$subs.length == $subs.filter(":checked").length ? true : false);
		});
	});
</script>
</head>
<body>
	<input type="checkbox" id="ckAll" />check all<br />
	<input type="checkbox" name="sub" />1<br />
	<input type="checkbox" name="sub" />2<br />
	<input type="checkbox" name="sub" />3<br />
	<input type="checkbox" name="sub" />4<br />
</body>
</html>